In the past, when values for the flow rate and volume passing through a pipeline or other fluid conduit have been desired, a metering orifice is normally installed and the pressure difference measured in order to determine the flow rate through the metering orifice. The addition of a metering orifice increases the pressure required to overcome the line losses through the pipeline, and is particularly undesirable in situations where the additional size, weight and/or pressure loss are of particular importance. The addition of a valve is necessary to control the repetitive injection or transfer of a fixed volume through the pipeline adding weight, cost and line losses to the system.